The invention concerns an apparatus for the transport and equipping of substrates with semiconductor chips.
With the mounting of semiconductor chips, it is customary to connect the semiconductor chips, mainly power semiconductors, to the substrate by means of soft solder in order to guarantee an effective dissipation of the heat loss from the semiconductor chip occurring during operation via the solder connection.
As substrates, metal substrates, so-called leadframes, are mainly used where the semiconductor chips are soldered onto chip islands arranged one after the other or, optionally, next to each other. The leadframe is fed in cycles to a soldering station where the solder is applied and then to a bonding station where the semiconductor chip is placed onto the liquid solder by a Pick and Place system. The leadframe has holes arranged along its longitudinal edge into which pins engage during transport of the leadframe. A Die Bonder suitable for this process is marketed by the applicant under the designation 2007 SSI.
Single position substrates, so-called singulated substrates, are also used. Such a single position substrate comprises, for example, a ceramic chip which is covered on both sides with a metal layer. Mounting of the semiconductor chips takes place manually in that a preformed portion of solder, a so-called solder preform, is first placed on the single position substrate and then the semiconductor chip is placed onto the solder portion. Afterwards, the entire composite is hard-soldered in an oven. A semiautomatic assembly process is also known with which, instead of a preformed solder portion, solder in the form of paste is applied mechanically to the single position substrate. Afterwards, the single position substrates are manually equipped with the semiconductor chip and again hard-soldered in an oven.
The object of the invention is to develop an apparatus with which single position substrates can be equipped fully automatically.
An apparatus in accordance with the invention for the transport and equipping of single position substrates with semiconductor chips has a channel with two side walls in which the single position substrates are transported in a transport direction. Feeding of the single position substrate takes place by means of toothed combs which can be raised and lowered and moved back and forth whereby each tooth moves one single position substrate forwards. Elements, resiliently-mounted in one of the side walls of the channel, have the effect that the single position substrates are pressed against the other side wall so that they are not swept away by the flow of inert gas prevailing in the channel.
The apparatus can also be set up for the transport of leadframes.